THE HARMONIZED MODEL John R. Herring Convener Harmonized Model Maintenance Group 1

History of Western Philosophy Bertrand Russell, 1946 One of the defects of all philosophers since Plato is that their inquiries … proceed on the assumption that they already know the conclusion to be reached.

References 3 Text (avoid “cookbooks”- too application specific)  The Unified Modeling Language Reference Manual — James Rumbaugh, Ivar Jacobson, Grady Booch — Addison-Wesley (2nd edition, 2005) Specifications  OMG Unified Modeling Language (OMG UML), Infrastructure  OMG Unified Modeling Language (OMG UML), Superstructure  OGC r3 The Specification Model — A Standard for Modular specifications

Purpose of the Harmonized Model  Harmonize ISO TC 211 standards  Define a common object-oriented vocabulary  Provide a common basis for implementations  INSPIRE  SEE Grid (solid earth environment grid)  Two inherent logical layers:  Conceptual – root of interoperability  Implementation – root of plug-n-play

HMMG Home — Links to –  Model data download  Dependency document.  An HTML view of the Harmonized Model  Publicly readable “subversion” repository from CSIRO’s SEE Grid web site.  Version of all parts, standards and work in progress.  Refreshed multiple times daily. 5

What the Harmonized Model is  A UML model defined (in pieces) by the official editions of ‘every’ ISO TC 211 standard  Through various human errors, there are some problems.  The HMMG has only limited authority to fix these  The Model shall match the documents  Minor fixes are done to align the model with the documents  Other problems are referred to “leads” and may result in corrigendum or other fixes. 6

UML in the HM  See Reference Manual cited  Is not a graphics editor  Is a set of formal graphics languages with well- specified meanings and interpretations  Can be some of many things:  Ontology, object design, resource design (REST), process design, system architecture  Well governed system; rules of use, flexible but strict  Layers of model and metamodel, abstractions: ’09, ’10  Compliance can be loose or tight: ’07, ‘36 7

Model procedures with repository  Edited with Enterprise Architect in (a local copy of) the Harmonized Model (to track GUIDs) – always!  Stored in a “subversion” repository at JRC.  Stored as XMI, each document, published edition – linkages by GUID, not names which may change  Management is done by EA and Subversion  New EA commands: check-out, check-in, refresh (often)  By document editor, or HMMG approved staff  Repository can “recover” the state after any transaction, from any date, state of model 8

Basic procedure with repositories RepositoryLocal Copy Check-out Edit Repository Check-in Transaction Edit … 9

Model procedure using copies 10  Editor begins with a new copy of the harmonized model  New package is created for each document/edition  Editor periodically (monthly?) posts his documents model to the HMMG  HMMG does a quick merge, update and post  Editor retrieves new copy of his doc in HM (all other documents are refreshed to current state)

Some limitations  Nothing changes unless the package is checked out before and checked in after (commits a transaction)  An editor should only check out his document  Elements in XMI are identified and linked only by GUIDs, globally unique identifiers  GUIDs enable round tripping of the XMI at any granularity (one package to whole model)  Multiple versions of same document mean no name uniqueness (especially within a series)– all linkages are by GUID 11

The Future — Direct repository use 12  Currently editions are posted through the HMMG leads, editors work in copies of the model  In the future, editors will access their own documents in the repository – transactions through local copies  The repository procedures will keep them from changing anything they do not own  Subversion tracks all changes, records all states and which user does what.

Known Issues (under work / debate)  Unit of reuse (OGC ‘Modular specification policy’)  Unit of reuse in a standard is the conformance class  Unit of reuse in a UML model is the package  In the future, UML packages in the harmonized model should respect conformance class boundaries  Direct Access to repository by editors  Plans to create an “partially editable mirror”  Working documents editable by PT/EC  Published documents read-only (maintained by HMMG, strict consistency rules – tagged for development processes) 13

Questions? 14 cover of New Yorker; August 4, 1986